Defensive publication

ABSTRACT

VERY SMALL QUANTITIES OF FERROUS IRON, I.E., ABOUT 0.4 PERCENT, CAN RESULT IN 20 TO 25 PERCENT SLUDGE FRACTION IN AMMONIUM AND POTASSIUM POLYPHOSPHATE LIQUID FERTILIZERS EVEN AFTER 1-2 WEEKS OF STORAGE, WHEREAS FERRIC IRON CAN ATTAIN CONCENTRATIONS UP TO 4.0 PERCENT WITHOUT THE FORMATION OF SLUDGE CONSTITUENTS. IT HAS BEEN DISCOVERED THAT TREATING THE WET PROCESS PHOSPHORIC ACID WITH A VERY MINOR QUANTITY (USUALLY ABOUT 0.3 PERCENT) OF AMMONIUM NITRATE WHILE THE ACID IS WARM (ABOUT 60* C.) WILL CONVERT THE IRON TO THE FERRIC STATE AND PREVENT THE UNDESIRABLE SLUDGE FORMATION OF FE(NH4,K)2P2O7 2H2O. OTHER NI TRATE SORUCES WHICH MAY BE UTILIZED AS OXIDIZING AGENTS ARE NANO3 OR KNO3. COMMON OXIDIZING AGENTS SUCH AS PERMANGANATES, DICHROMATES, PEROXIDIES, CHLORITES, HYPOCHLORITES, AND OTHERS ARE EQUALLY EFFECTIVE BUT ARE NOT AS INEXPENSIVE AND UNIQUE AS AMMONIUM NITRATE WHICH IS NOT USUALLY CONSIDERED AS AN OXIDIZING AGENT. THE REQUIREMENT FOR THIS TREATMENT AND QUANTITY OF AMMONIUM NITRATE NEEDED CAN BE READILY DETERMINED BY A SIMPLE TITRATION OF THE ACID USING A STANDARDIZED POTASSIUM PERMANGANATE SOLUTION.

UNITED STATES PATENT OFFICE Published at the request of the applicant or owner in accordance with the Notice of Dec. 16. 1969, 869 0.G. 687. The abstracts 01 Defensive Publication applications are identified by distinctly numbered series and are arranged chronologically. The heading of each abstract indicates the number of pages of specification, including claims and sheets of drawings contained in the application as originally filed. The files of these applications are available to the public for inspection and reproduction may be purchased for 30 cents a sheet.

Defensive Publication applications have not been examined as to the merits of alleged invention. The Patent Oflice makes no assertion as to the novelty of the disclosed subject matter.

PUBLISHED SEPTEMBER 21, 1971 T890,012 STABILIZATION 0F POLYPHOSPHATE FLUID FERTILIZERS BY ()XlDlZllNG AGENTS Alva W. Frazier, 2219 Randolph St, Florence, Ala. 35630 Filed Dec. 23, 1970, Ser. No. 101,094

' lint. Cl. (105i) 7/00, 13/06 r US. Cl. 71-34 No Drawing. 14 Pages Specification Very small quantities of ferrous iron, i.e., about 0.4 percent, can result in 20 to 25 percent sludge fraction in ammonium and potassium polyphosphate liquid fertilizers even after 1-2 weeks of storage, whereas ferric iron can attain concentrations up to 4.0 percent Without the formation of sludge constituents. It has been discovered that treating the wet-process phosphoric acid with a very minor quantity (usually about 0.3 percent) of ammonium nitrate while the acid is warm (about 60 C.) will convert the iron to the ferric state and prevent the undesirable sludge formation of FC(NH4,K)2P2O7'2H2O. Other nitrate sources which may be utilized as oxidizing agents are NaNO or KNO Common oxidizing agents such as permanganates, dichromates, peroxides, chlorites, hypochlorites, and others are equally elfective but are not as inexpensive and unique as ammonium nitrate which is not usually considered as an oxidizing agent. The requirement for this treatment and quantity of ammonium nitrate needed can be readily determined by a simple titration of the acid using a standardized potassium permanganate solution. 

